# Wire body bytes and the Content-Encoding the server chose (curl 7.84.0+ for %header{}).
curl -sS -o /dev/null -x "$PROXY_URL" \
  -w '%{size_download} %header{content-encoding}\n' https://example.com/
curl -sS -o /dev/null -x "$PROXY_URL" --compressed \
  -w '%{size_download} %header{content-encoding}\n' https://example.com/